1. Field of the Invention
The present invention relates to a process for manufacturing a reproduction with a luminescence effect, and to such a reproduction.
2. Background of the Invention
It is currently known to make reproductions with a luminescence effect and more specifically a photoluminescence effect of the positive or negative Chinese-shadow image type or images produced using colored photoluminescent pigments. These two types of images having a luminescent effect are essentially produced using the following processes:
by screen printing and optionally offset printing with photoluminescent inks which are colored or not on various carriers, such as paper, fabric, plastic or metal;
by various forms of printing (screen, xe2x80x9cpressure-padxe2x80x9d, offset, heat-transfer printing, etc.) on photoluminescent carriers by means of non-photoluminescent inks; and
by superposition of a carrier which is opaque or non-opaque, colored or noncolored, perforated and/or rendered opaque at chosen places allowing the luminescence of a second luminescent carrier to appear at the perforated places and/or at the transparent places.
These various processes do not make it possible to produce reproductions having a very high resolution and very sharp images, which may be seen quite faithfully at night as they are during the day. These are often rather simple, geometrical drawings with few details and few colors. In addition, the colored photoluminescent pigments offer only a limited number of colors and their luminescence characteristics, both in terms of brightness and in duration, are limited. In all these reproductions, one element which has a strong negative impact on the rendition of the image is the color of the luminescent product, which is often yellow.
The object of the present invention is to make it possible to produce, as a reproduction with a luminescence effect, all types of images such as photographic images, technical drawings, artists"" works, artificial images, logos, texts, wood-, stone-, metal-, fabric-, liquid-, plant-texture effects, or any other extra effects. These reproductions are produced with a very high quality of detail, of sharpness, of contrast and of colors, while allowing the luminescent image to be very bright and to last longer than that of the current state of the art.
The process according to the invention is characterized by the fact that the following steps are carried out:
a. a film comprising a luminescent material is prepared;
b. a translucent filter is prepared in order to form a cohesive interface between the luminescent material and a surface provided with an image and to moderate the influence of the color of the luminescent material on the rendition of the reproduction; and
C. an image is printed on at least one surface allowing light to pass through it, ensuring that it is transparent.
The advantage of the process according to the invention is that it makes it possible to print any type of image while maintaining its quality, i.e. its shades, its colors and its details, whether the printing is continuous-tone printing, for example laser printing, or positive or negative photographic printing, in order to obtain a photographic quality, or very fine halftone printing, for example offset printing, or full-color area printing, for example screen printing. The condition is that this printing be transparent and produced on one or more surfaces allowing light to pass through them so that the luminescent material can be reached by the light in order to store the light energy optimally, when it is a photoluminescent material, and above all to allow said energy to be regenerated by the light emission from the product through the reproduction and said surfaces. The luminescent material is, of course, preferably photoluminescent, but other materials which may be charged by other forms of energy, such as electrical energy, may be used. If the luminescent product has a color which impairs the quality of the reproduction, a suitable translucent filter must be provided. This filter may either be a film placed over the film with the luminescent product or be incorporated directly into the film with the luminescent material.
According to another embodiment, provision is made to print the image on the filter using known means, for example heat transfer, offset, screen-printing, etc.
According to another embodiment, the image is printed directly on the film with the luminescent material incorporating the filter, the surface on which the image is printed always being a surface allowing light to pass the though it.
According to another embodiment, the image is printed on a transparent carrier which is then affixed to the film comprising the luminescent material and to which the filter is affixed.
According to another embodiment, the image is also printed on a transparent carrier which is affixed to the film comprising the luminescent material and the filter.
According to another embodiment, for the purpose of optimizing the light emission from the luminescent material, a backscattering film is applied to the back of the film incorporating the luminescent product.
According to another embodiment, the image or parts of the image which are juxtaposed or superposed is/are printed on two different surfaces allowing light to pass through them, thus making it possible to obtain a depth effect and, where appropriate, a relief effect.
This is because it is possible, in the simplest case, to print the entire image or parts on two faces of a transparent carrier which is then affixed to the film with the luminescent material, the filter having been affixed beforehand to said film or incorporated into the luminescent material.
It is also possible to print part of the image, for example the background, on the filter and the other on a transparent carrier, or else to print part of the image on the film comprising the luminescent material and the filter and a transparent carrier. In the latter case, the transparent carrier could also be printed on both faces, completely or partially, thus creating a relief effect in addition to a depth effect. If superposed parts of the image are printed on different surfaces and in different colors depending on the angle of observation, the superposition of the colors will also modify the color of the reproduction.
The invention also relates to reproductions obtained by the implementation of the process according to the invention.
Thus, a reproduction with a luminescence effect is characterized by the fact that it is composed of a film comprising a luminescent material, of a translucent filter and of an image printed on at least one surface allowing light to pass through it.
According to another variant, the image printed completely or in juxtaposed and/or superposed parts on two different surfaces allowing light to pass through them, thus making it possible to create a depth effect and, where appropriate, a relief effect.
Finally, the reproduction may comprise a simple transparent protective screen, in particular a screen for protection against ultraviolet radiation.